Aircraft landing wheel prerotation means



Sept. l2, 1950 M. w. MORSE AIRCRAFT LANDING WHEEL PRERoTATroN MEANS 4 Sheets-Sheet 1 Filed July 30, 1945 IN V EN TOR.

Sept. 12, 1950 M. w. MoRsE 2,521,864

AIRCRAFT LANDING WHEEL PREROTATION MEANS Filed July 30, 1945 4 Sheets-SheetLZ IN V EN TOR.

Mmmm BY AW Sept. 12, 1950 M. w. MORSE AIRCRAFT LANDING WHEEL PREROTATION MEANS 4 Sheets-Sheet 5 Filed July 30, 1945 's z lf- INVEN TOR. a/065m d manu. www

M. W. MORSE AIRCRAFT LANDING WHEEL PREROTATION MEANS Sept. 12, 195o 4 Sheets-Sheet 4 Filed July 30, 1945 INVENTOR. awm [A] )77m MMT 2,521,864@ A Antennrr 'LANDING WHEEL' :ennn'ornnlou `Malcolm WlcoxMorse, Wllesl'eyill'sm n Application July so, 1945,'serialncyeiigi3usl p,

reclaim-s. (ci. 244-403) j This invention has for its object vto provide novel means vfor e'i'l'ecting the rotation vand rcontrolling the speed of rotation of the landing wheels vlof aircraft and more particularly for overcoming 'the inertia of the landing wheelsfand effecting the prerotation lthereof prior to lande ing Ato cause the peripheral'spee'd thereof to approximate the ground speediof the'aircraft when landing. l

Aircraft, as is 'well-'known are provided with landing wheels vmounted "in various positions and usually retracted during',v flight and 'moved' to landing position prior toianding. These wheels maybe located either beneath the"fuselage' at the nose, central part, Aortail, or beneath the wings, the particular location dependilig upon the size and type of the aircraft. Each wheel is usually composed 'of a central c irumand -a 'heavy pneumatic tire. The VWheels in each Vlocation are either single lor in pairs. YIn the caseof 'the 'large and powerful'air'crait, such as 'the bomber type,

these Wheels are very large and heavy often Weighing a half ton or more apiece. At present bombers, transports, land other large 'aircraft usually land ata fairly high speed `'and if Vthe landing wheels lareniotionl'ess in' the retracted position 'and not rotating before being lowered preparatory to landing soas to have a 'peripheral speed `approximating `the 'ground speed of the aircraft when the landing takeszplace orat v'the'instant of contact of the ground, there 'results extreme stress vand Wear upon the tires o'fjthe wheels dueto the Vdrag of the 'Wheels while under the Vheavy load on -the surface 'of lthe ground.

In the present inventiony driving means are provided'which Y'operate directly upon the periphcries of the landing Wheels so that the power to eiect prerotation is 'applied in the most 'efficient manner. Furthermore, in order to overcome the inertia to prerotation, the driving means arep'referably operated at a variable lor gradually accelerated speed until the 'prerequisite speed is obtained.

The invention also has forv its further 'object to provide various novel means foreiiecting 'the prerotati'on of the land'ingwheels through the pe'- riphery thereof. l

These and othery objects ofthe invention `will appear more fully `from:theacconipanying del4 theaircrait where theylarefmcunted. the Ymeans employed'fcr in'cving he'ilanuing till-eers between retiactedjandjlanding positions, it is only necessary here, 'to 'illustrate 'and v describe so much 'ci certain 'types of landine'wheel construction 'as is l present invention;

vin*the"dra'iffines Fig. '1 is a-sideze'l'evatlcn, partially diagrammatic; "or a' `-landing wheel construction compris# suhicient'to diserosethe .nature and scope of "the ing a strut having a pair of landing wheelslvvifth" the strut pivoted at its upper end 'to allow theA movement oi thelandng "Wheels 'between a yre trcte'd pOStlUn 'With Strut Substantially "horlzofrital and Valain'ding pdsitionwth the 'strut sbp stantial'ly vertical, the former v"ifl'ositiorl being shoivnin fu'll `lines and thelatter in dotted lines; Fig. 2 `a '110131121931 View 0f th 'malin ftl'ls of the construction shoWnin Fig. 1.

Fig. 3 "is "a front' 'elevation 'of `another form 'o'f construction yeiiibotlying 'the invention of which' the iti-'ridingy wheel and its ieg or strutls pivotallv mounted to move vrlaterally 'between retracted 'positions within the Wings of the aircraft and landing position. t

Fig. "4 is affront lelevation of anaircraft sliovv ina a pair of landing "wheels mounted so as rri'ovefas illustrated in fFig. 3.

Fig. 5*'is an underneath .plan `view of the construction sliown in Fig. '8.

Referring ir'st to 'theconstruction illustrated-y in Figs. 1 'and"2,`th`e fl'eg orstrut l, '2 is of the' usual ltype 'inwhi'ch 'tiiejperul telescop'ed' within the .part l, is :yieldingly pressed outwardly and in which the strut is pivoted 'at a shaft 3 "in 'a suitable position 'in 'the aircraft. At the outer end of 4part 2 ofthe lstrutare journaled a 4pair loi" landing wheels 4 with the usual .anti-shimmy hinge :construction consisting of ithiev links '5 pivoted tog'ether with Ionepivotally 'connected 'to the` lower end ofthestrutpart 2 'and the other "pivotallyl-connected'tothe collar r6 on thestrut part l. Suitable means vincluding the connection 'l are provided under the lcontrol 'or the pilot .for swingingtnis `landingvs/heel Vconstruction lcetvveen `retractecland landing 'positionsv All of this construction'tnus "far indicated is well known and familiari-and may be 'of any 'Sl'iitalileV type.

in connection with this construction two land-v y ing Wheel peripheral engaging` prerotation driv'-l ing means arefdisclosed. nfraine 8 is `located opposite-the" landing wheeis in' the retractedpost' tion-and `=pivotedjat f Ito a fsi'iitable vsupport on the aircraft; Pulleys li `'are.1j"ournaledon the pivotal axis-oi, this 'ranieand .pulleys 1'2 on an Vaxis near' 'iss'ithe upper-end of 'theirauie A pair ofi endless driving; meansi into.; operai-ioni tlfirouelmn theccorrf;Y @61st thusfby reasornotl the;l principles employed;l readily: overcoming.: the; inertia. .oe the; driving: Wheels. tofvrotation; andf through the;` application:- ofl thepowento. .the nerinheries where;E it; is; most; emoientlr employed fread-ilu` effects; arprerrotation;

of i the landing wheelsgat; the requirredspeed which would usually'be determined so asotossynohronize;

with the predicted ground speed osth'ajaroraft,

ing position. But if a still more accurate control of the periphral'speed-be* desired', theprinciple employediin the constructionillustrated in Figs.` 1 .and 2 may he utilized andthefperipheralspeed thuegaccurately Controlled. upftoithe imnactzfof landing. In such case, of course, the controls wauld be` manipulated to secure-:a synchronization of; the speed of the two sets` of drilling belts 'when the landing wheelsare in retractedposition;` .And it,is,:of} course, understood thatfn all Caseszt willfbe desirable through tha-controls to stop; the operation of, the drivingmeansfwhen the-landing wheel leaves.. the retracted position-or whenthe lendnsiwheelreacheslanding position.

In the event that the landingwheel construction is of a non-retractabletype; it is obvious that the principle of the invention may be applied. byfthe.A `use,;or example, of. thatixportion 1, ofi. the construction shown in Figs. 1 and 2 where the wheel periphery engaging driving means are mounted upon the support for the wheels.

The landing wheels will preferably be provided with the usual braking means under the control of the pilot or operative so that if the peripheral speed of the landing wheels exceeds that desirable in relation to the ground speed of the aircraft when landing, the speed of the wheels may be reduced by the braking means.

While in the construction illustrated in Fig. 1, the motor and speedometer mechanism employed in connection with the driving means which moves bodily with the landing wheels between retracted and landing position are shown in xed position on the aircraft with the flexible drive extending to the driving means, it is obvious that the fixed position of these elements is but illustrative and that they may be mounted and moved with landing wheels.

Throughout the development of this invention the importance and necessity has been recognized that nothing be placed in contact with, or anijacent to, the landing wheels and other parts of the landing gear which could, through mechanical failure or motive-power failure, prevent or hinder the operation of lowering of said landing gear into the required position for landing of the aircraft.

Because of this consideration it will be noted that the various prerotation means, have been purposely designed to @so located in such manner and at such angles of contact to the peripheries of the landing wheels and in such positions that should there be mechanical breakdown of or motive-power failure to the several prerotation means the wheels of the landing gear would easily roll out of contact with said prerotation means when they were caused to be lowered into landing position by means separate from and independent of any mechanism of the prerotation means.

Also in types where provision has been made for Lil 6." auxiliary.ziprerotationvmeans iattacliedlto landings-i geanand; movable therexizitl'q; i.prrruiision:Av hasi: also. beenzmarii-i..so thatzinxthe; :event that thesemeans arelinoperativevfor.any I-reason'; ith'eyzwill be .auto-A maticailyi` andi` instantly:i disengaged from contactb with the len-ming.wheels,` at'; thenrmoment-.ieof-i e: contact between the lowered landing wheel .and surface on which. the: aircraf-t5isfiflanding. f .-1

Having thus described; theginvention;what;y -is z claimed asinewg, and desired tmbelfsecuredlbyl. LettersPatent;isi..y l: f

'Ehe :combination with: anizaircraftqhavin az; landngiv wheelfniountedi thereorri-fonmovements betweenk afretraoted .positionr anday the l* landings positioniert twof` setsioff driving-means:frictionallyc; engageable; with-.the` wheel periphery' when'l the wheeli is inrretr-acted position, means for-:operati-g ing'p-.both idriving;meanszzinisynchnonismz'to effect; prerotation. of the.; wheel;v preparatory; t landings.: one:set;oirsaid:drivingsmeans'lbeing:mountedifori: movement in?` .frictional engagementy with ,theirv wheel from retracted;pnsitiomt'o4 landing;position` 2.1; The ALcombination with 4aircrafthavingia landing. wheel, provided -withi.arrubberftiregand@ movable between. a1: retracted position'A and; the; landing positiomof; driving` :meansav comprisinge endless belt'A contacting; .the outer: peripherals segment.. of,l .the tire...tangential/thereto: whencthei.. wheeii in; retracted.'position,`v andivm'eansi'a.fon"A operating, the: 4.rendlesa belt to. .feffectz prerotatio'rr.A off.theawheelipreparatory;tlandingis' f l 3:; ,Theiconstructiongdeneds iruclaimtog'fethen: with means acting to move the driving means bodily toward the landing wheel when in retracted position thus acting upon movement of the landing wheel into retracted position to cause the endless belt to press into rmer frictional engagement with the wheel periphery.

4. The combination with an aircraft having a landing wheel provided with a rubber tire, of driving means comprising an endless belt contacting the outer peripheral segment of the tire tangentially thereto, and means for operating the endless belt to eiect prerotation of the wheel preparatory to landing.

5. The combination with an aircraft of a supporting strut part movably mounted thereon, a second strut parttelescoping with the nrst, a landing wheel provided with a rubber tire pivoted on the lower end Iof the second strut part, means for moving the strut parts to carry the Wheel between a, retracted position and the landing position, driving means frictionally engageable with the outer peripheral segment of the tire tangentially thereto and movable in such engagement with the tire from retracted position to landing position, means for operating the driving means when in retracted :position and during the movement thereof from said retracted position to landing position, a, connection between the second strut part and the drivingmeans acting to move the driving means out of engagement with the wheel by the telescoping movement of the second strut vpart upon landing impact.

6. The construction dened in claim 5 in which the driving means is pivotally mounted on the rst strut part and in which the connection consists of a link connecting the second strut part to the driving means.

7. The construction defined in claim 1 together with a telesooping strut movably connected to the aircraft, means for mounting the landing wheel upon the lower portion of the strut, means for mounting that driving means which is in frictional engagement and movable with the landing wheel uponthe upper portion of the strut, and a connection betweenl the lower portion of the strut and lthe driving means'acting to movel the said driving means bodily away from engagement with the Llanding wheel by :the telescopingv thereto when the wheel is in retracted position,-

the landing wheel into retracted position to cause the endless belt to press into firmer frictional engagement with the wheel periphery.

10. The combination with an aircraft of a supporting strut -part movably mounted thereon, a

second strut'part telescoping with the first, ai landing ywheel pivotedon the lower end of the: second strut part, means for' moving the strutv parts to carry thewheel between a retracted position and the landing position, driving means frictionally engageabie with the outer peripheral so segment of the wheel tangentially thereto andv movable in such. engagement with the wheel from retracted position to landing position, means' for' operating the driving means when in retracted position and during the movement thereof .from' saidy retracted positioxrto landing position, a con- Y- nection between the second strut part and the driving means acting to move the driving means out ofy engagement with the wheel by the telez scoping movement of the second strut part upon" landing impact.

REFERENCES CITED The following references" are ofr record in' th;

file of this patent:

k UNITED STATES PATENTS Number Name Date 1,834,427 Schumacher v Dec. 1, 1931 2,063,032 y Fatox' Dec. 8, 1936 2,264,923 Waseige Dec. 2, 1941 2,305,237 Carpenter Dec. 15, 1942 2,320,547 Tiger June 1, 1943 2,347,986 Powerman May 2, 1944l 2,370,316 Juul Feb. 27, 1945 2,389,525 vManheim Nov. 20, 1945` 2,399,218 VFeldiburg Apr. 30, 1946 2,408,870 Murdoch Oct.8, 1946 2,417,937 Knox Mar. 25, 194,7`

' FOREIGN PATENTS Number Country Date MALCOLM WILCOX MORSE.

France Jan 2, 1930 

